1. Field of the Invention
The present invention is related to a hand-held wireless computer controller system which includes a hand-held terminal and a computer interface transceiver connectable to a computer. More particularly, the present invention is directed to a system which includes a compact battery powered wireless control station which securely transmits alphanumerics and control functions to a receiver which is interfaced to a computer via a RS 232 serial link. The receiver echoes back the transmitted information and the hand-held station displays the echoed back information on a display.
2. Description of the Related Art
Conventionally, communication with a computer is done by way of a hardware terminal which is bulky and not portable. The need for more lightweight and portable computer type terminals has resulted in the development of two types of portable terminals.
One is the type commonly associated with license checking systems used by the police. This system includes a host computer 10 communicating to a master terminal 12 through a multiplexor 14 to plural remote terminals 16-18. The remote terminals in this system are bulky, consume large amounts of power and would not be appropriate for a pocket sized terminal which could be used in a teaching environment in which the teacher would wander over a relatively confined area such as associated with a nuclear power plant simulator.
Another type of terminal is available in which a tethered hand-held terminal 20 is connected to a host computer 22 via a multi-pair cable 24. This system, even though it can provide a very compact terminal, suffers from the drawback of extremely limited range of movement because of the cable 24 which can be rather bulky and cumbersome to drag around. In addition, the attached cable 24 will not allow a teacher to comfortably stick the terminal 20 in a shirt or coat pocket. The more or functions or keys provided on the hand-held terminal 20, the larger and more bulky the cable 24 becomes.
A wireless hand-held terminal has also been developed which has only a transmit capability. The number of keys and, therefore, codes transmittable by the unit is also limited by the use of a pulse-width modulation transmission technique. The unit also does not include a display so the operator is always left guessing concerning whether the correct code has been transmitted to the host computer.